1. Field of the Invention
The present invention generally relates to an IC card reading or reading and writing apparatus (hereinafter referred to as IC card reader/writer apparatus) which is adapted for reading or writing information or data from or in IC cards each incorporating semiconductor circuits such as a microprocessor, memories and others. More particularly, the invention concerns an IC card reader/writer apparatus which can assure high security of information contained in the IC cards by adopting such an arrangement that reading or writing of desired information is not allowed to be carried out unless two or more cards are inserted in the apparatus.
2. Description of the Related Art
In general, the IC card reader/writer apparatus is implemented in such a structure in which after loading of an IC card in the apparatus in an inserting port (referred to as contactor), cipher code or password (e.g. a string of numerals or symbols or combination thereof) only known to the card holder or user is inputted to the apparatus, being followed by comparison of the inputted cipher code with a relevant cipher code stored in the card or a host computer to which the card reader/writer apparatus is connected, wherein upon coincidence in the comparison, the writing of data (information) in the card or the reading of the data from the card is permitted. The hitherto known reader/ writer apparatus is equipped with only one contactor. Consequently, when the card reader/writer apparatus is employed in an information management system in which a plurality of card holders or users are registered, the processing for writing or reading data in or from a single card is carried out individually independent of the cards owned by the other card holders.
As a typical example of the information management system, there can be mentioned an overall medical management system in which information concerning health condition, case histories, results of inspections, contents of diagnoses, medications and dosages and the like of a person or patient is recorded in an IC card. On the side of the patient, the card is made use of for the purpose of management of his or her health, the recording of medical payment and others, while on the side of the doctor, the card is utilized for recording or retrieving data for medical treatment, calculating the amount of medical fee, accounting and the like.
In the card management system of the type described above, it is not permitted from the stand point of securing the privacy and in view of the monetary contents of the card that anyone can write or read freely the diagnostic data or medication data in or from the card without authorization, but strict maintenance of the security of the information is required.
In the case of the hitherto known IC card reader/writer apparatus employed in the card management system, the patient and the doctor possess respective IC cards, and both parties can write or read the data of the kinds mentioned above in or from their own cards, respectively, independent of each other. In other words, the reader/writer apparatus is equipped with only one contactor and so designed as to be capable of processing the data of a single card without regard to the other card. Under the circumstances, there may arise such cases in which the medication data and treatment data are written in the doctor's card without being known to the patient who is thus compelled to make undue payment or in which the data concerning a patient are read out by using the doctor's card without encountering any restriction in a hospital, giving rise to a problem that the security of the information might be endangered. In addition to the overall medical management system mentioned above, there are also known commercial transaction management systems used in retail stores as well as wholesale shops in which customers have respective cards for recording the amounts of purchases day by day for settling accounts at a time later on. In the case of this system, the data of the amounts recorded in the IC card prepared for each customer and managed by the store must necessarily coincide with the data recorded in the IC card possessed by the customer. Accordingly, the card management system has to be so implemented that one party can not freely make access to the contents stored in the card without authorization of the other party. However, in the case of the system in which the hitherto known card reader/writer apparatus each equipped with only one contactor are employed, there exists a possibility that one party may perform modification or alteration of the data contents stored in the card intentionally or accidentally without being authorized by the other party. Thus, there exists a problem concerning the security of the information stored in the IC card.